Simulation Single Screw Extruder

Single screw extruder CAD groups and surface mesh

Figure 1: CAD model created in NOGRID's COMPASS

Single screw extruder GUI setup and initial conditions in NOGRID points CFD software

Figure 2: Setup the extruder case within the GUI

Single screw extruder GUI results in NOGRID points CFD software

Figure 3: Extruding state at a certain time step

Animation single screw extruder, computed in NOGRID points CFD software

Figure 4: Short animation of the extrusion process

With the simulation of a single screw extruder the meshless CFD software NOGRID points provides valuable insights into the internal flow behavior. Simulating screw extruders is crucial for optimizing extrusion effiiciency and ensuring consistent product quality. NOGRID software delivers accurate simulations for a wide range of extruder designs.
In this example, a barrel with a constant radius is shown, featuring an inflow area at the top. A Newtonian fluid with a viscosity of 1 Pas is injected at the inlet, gradually filling the extruder over time.

Functions of screw extruders

In this example, we solve the complete Navier-Stokes equations, including temperature transport. Screw extruders, commonly used in the healthcare and food industries, represent a highly important class of pumps for processing non-Newtonian materials. Depending on the application, one key function of the screw pump is to transport fluid while minimizing shear in the channel between the screw and the barrel wall.

Implemented models in NOGRID points

In this case study, the single screw extruder is initially empty and gradually filled with fluid over time. This example also demonstrates the free surface capabilities of the NOGRID fluid simulation software, as it allows for the simulation of partially filled extruders. While the viscosity of the fluid is constant in this simple case, the NOGRID points CFD software includes a wide range of non-Newtonian material models for more advanced simulations:

Bird-Carreau-Yasuda with and without WLF shift:
The Bird-Carreau_Yasuda model is a general model for capturing strain-rate dependent viscosities in polymer rheology. At small strain rates, it behaves like a Newtonian fluid with (almost) constant viscosity. For very large strain rates, it resembles the power law. The Williams-Landau-Ferry model adds a temperature dependent shift factor.
Carreau with and without WLF shift
Cross with and without WLF shift
Menges-Wortberg-Michaeli
Power law
Bingham-Herschel-Bulkley-Papanastasious

Features of NOGRID points software

The CFD software NOGRID points provides valuable insights into the flow behavior within a partially filled single screw extruder. The screw (or auger) serves to reduce friction and support cooling, with the effectiveness of cooling depending on the screw size and the fluid transport rate. NOGRID CFD software combines the capability to simulate free surface flows and moving parts within the computational domain, enabling the simulation of any screw geometry and operating mode, such as:

fully 3D computation solving complete Navier-Stokes equations
easy and intuitive setup also for partially filled extruders
freely definable material properties by equations or curves
injection by one or more inlets
open or closed domains including moving of additional parts
moving and rotating of the screws

Whitepaper PUR Foaming

Why choose Nogrid?

NOGRID provides professional CFD software for the simulation of fluid flow, heat and mass transfer, and chemical reactions. Its efficient modelling workflow helps engineers analyse flow behaviour, evaluate designs and make informed decisions without creating a conventional volume mesh.

Faster model preparation

With NOGRID, only the geometry boundary needs to be meshed. The finite points inside the fluid domain are generated automatically according to user-defined settings, both at the start of the simulation and during the calculation.

This approach reduces preprocessing effort and makes it easier to prepare complex geometries and cavities for simulation.

Efficient CFD workflow

The modelling process follows four straightforward steps:

Build the geometry. Mesh the boundary. Define the simulation. Start the calculation.

NOGRID is designed to provide short computation times, including for applications involving complex cavities. Engineers can use the resulting data to examine flow distribution and other relevant flow characteristics.

Better insight into fluid-flow processes

CFD solves the fundamental equations governing fluid flow. NOGRID software enables engineers to predict and analyse the behaviour of fluids and related physical processes before or alongside physical testing.

The simulation results can support:

evaluation and comparison of design alternatives
optimisation of construction and operating parameters
improved planning reliability
reduction of development time and testing effort
faster progression from design to market or operation

Steps from geometry generation to simulation results

TRAINING

Our two-day training courses teach participants how to set up, run and evaluate simulations efficiently with NOGRID CFD software. The courses include practical guidance for handling different types of simulation cases.

For more details please refer to Training Courses →

Technical Support

Professional support is available from the beginning of your work with NOGRID. Our technical team assists users by telephone and email with software operation, case setup and simulation-related questions.

For more details please refer to Software Support →

Simulation Service

When internal time, expertise or resources are limited, NOGRID can support your project with individual numerical simulation services. Our engineers develop and evaluate CFD models based on the specific requirements of your application.